title: Programmable gain amplifiers with DC suppression and low output offset for bioelectric sensors.
abstract: DC-offset and DC-suppression are key parameters in bioelectric amplifiers. However, specific DC analyses are not often explained. Several factors influence the DC-budget: the programmable gain, the programmable cut-off frequencies for high pass filtering and, the low cut-off values and the capacitor blocking issues involved. A new intermediate stage is proposed to address the DC problem entirely. Two implementations were tested. The stage is composed of a programmable gain amplifier (PGA) with DC-rejection and low output offset. Cut-off frequencies are selectable and values from 0.016 to 31.83 Hz were tested, and the capacitor deblocking is embedded in the design. Hence, this PGA delivers most of the required gain with constant low output offset, notwithstanding the gain or cut-off frequency selected.
authors.affiliation: Laboratory of Electronics and Bioengineering, ETSI de Telecomunicación, Universidad de Valladolid, Campus Miguel Delibes, Paseo Belén, 15. Valladolid 47011, Spain. ramros@tel.uva.es.
authors.forename: Albano
authors.initials: A
authors.lastname: Carrera
authors.forename: Ramón
authors.initials: R
authors.lastname: de la Rosa
authors.forename: Alonso
authors.initials: A
authors.lastname: Alonso
mesh_terms: D000669:Amplifiers, Electronic; D017076:Computer-Aided Design; D003217:Conductometry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D059629:Signal-To-Noise Ratio; D014159:Transducers